Piano action



Oct. 20, 1942., J. c. POTWIN 2,299,656

PIANO ACTION Filed May 8, 1941 Patented Oct. 20, 1942 UNITED STATEA'S PATENT OFFICE 10 Claims.

This invention relates in general to piano actions and in particular to improvements in a drop-type action for a low upright piano.

In piano actions. generally a proper adjustment of the back check relative to the hammer is essential in the efficient operation of the action to provide for a rapid repeat playing of the piano key and to eliminate any rebound action of the hammer against the piano string after the string has already been hit. In one form of drop type action in the prior art having the usual hammer, abstract and whip, the back check for the hammer includes a check wire and is supported on the Whip near the bottom of the action intermediate the abstract and the hammer and in a position below the level of the abstract and hammer. Adjustment of this back check is accomplished by bending the check wire in a direction substantially toward and away from the hammer. However, because of the assembly position of the back check in the piano action it is relatively inaccessible for manipulation so that this adjustment is an awkward and clumsy operation which is accomplished only with considerable inconvenience and much loss of time.

It is an object of this invention, therefore, to provide an improved drop-type action for a low upright piano.

It is another object of this invention to provide an improved back check for a piano action which is quickly and positively adjustable to an adjusted position relative to the action hammer.

A still further object of this invention is to provide an improved back check for a drop-type piano action which is simple and rugged in construction, comprised of a minimum of parts which may be inexpensively manufactured, and which is readily adapted for adjustment relative to the remainder of the piano action by readily accessible and simply actuated adjusting means.

A feature of this invention is found in the provision of an improved back check for a droptype action which is assembled in the action intermediate the action hammer and abstract so that an open space is provided above the back check and between the hammer and abstract, with means for adjusting the back check relative to the hammer being arranged so-as to be readily accessible for manipulation through such open space.

Further objects, features, and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. 1 is an elevation partly in cross section of one of the units of a complete piano action showing the improved back check or" this invention in normal assembled position therein;

Fig. 2 is a fragmentary side view of a portion of the piano action showing a modified form of the invention; and

Fig. 3 is a View illustrated similarly to Fig. 2 showing yet another modification of the invention.

In the practice of this invention there is provided a drop-type piano action having a plurality of abstracts, all simultaneously connectible or clisconnectible with corresponding piano keys as an incident to their assembly or disassembly, respectively, of the action and piano keys. Each abstract is pivotally connected at its lower portion to a corresponding whip which in turn is in operative connection with the usual hammer. A back check for the hammer is supported on the whip between an abstract and hammer so that an open space occurs above the back check and between the hammer and abstract. Means for moving the back check to an adjusted position relative to the hammer butt is arranged so that manipulation thereof for adjustment purposes is readily -accomplished by the insertion of a hand or some supplementary tool between the abstract and hammer and downwardly through such open space.

With reference to the drawing there is shown in Fig. 1 a piano action which is supported principally on a rail l0 which in turn is mounted on a plurality of mounting brackets H. A whip I2 is pivotally connected at one end to the rail l9 and in turn pivotally supports a jack or fly I 3. As the whip I2 is raised the jack [3 engages in the usual manner, the butt M of a hammer Hi, this motion being transmitted through the jack to pivot the hammer into striking engagement with a corresponding piano string. The whip portion 19 of an abstract 2| is pivotally connected near the opposite end of the whip l2 by pin 22, the abstract head 23 being in abutting enga ement with the capstan screw 24 which is mounted at the rear end of the piano key 26. A back-check l1 and bridle strap wire !8 are both supported on the whip, intermediate a corresponding abstract and hammer. With the units of the piano action arranged relatively close together longitudinally of the action, this assembly position of the back-check rearwardly of the abstracts and below the level thereof greatly restricts the accessibility thereto for adjustment purposes. However, as is clearly indicated in Fig. 1, the hammer and abstract are spaced laterally of the piano action so that the space immediately above the back-check is entirely open. To facilitate and simplify the adjustment of the back-check relative to the hammer butt portion 27 it is contemplated in the present invention that adjustable means be provided on the backcheck in a position readily accessible for adjustment through this open space occurring above the back-check and between the hammer and abstract.

Thus with reference to Fig. 1 the back-check H is illustrated as including an upright portion 28 comprised of wire or like material and supported at its lower end on the whip I2 in a fixed position relative thereto. On the upper end of the supporting member 28 there is mounted a supporting portion 23 of substantially inverted T-shape. the upwardly extending portion thereof being bifurcated to provide a pair of leg members 3! adapted to pivotally support therebetween a back-check shoe portion 32. The portion 32 is also of substantially inverted T-shape, its upwardly extending leg having a felt covering 33 on one side thereof for operatively engaging the hammer butt portion 21. In its pivotally supported position on the leg members 3!, as by a pivot 34. the lateral projections 3b and 33' of the shoe portion 32 are positioned relative to the corresponding lateral projections 3'! and 3? of the su porting member 23 so as to be pivotally movable relative thereto.

A screw member 38 is threadably supported in and extended through the projection 36' with the lower end thereof in abutting engagement with a felt portion 39 which covers the upper side of the supporting member projection 3?. The adjustment portion of the screw 38 extends upwardly from the projection 36' so as to be readily and easily gripped from a position above the back-check and between the abstract 2! and hammer IS. A spring M is arranged in compression between the projections 36 and 31 to maintain, in an obvious manner, the position of the shoe portion 32 as determined by the rotation of the screw 38. It is readily apparent therefore, that any pivotal movement of the shoe portion 32 about its pivotal support 34 changes the position of the felt engaging portion 33 relative to the hammer butt portion 2'! to in turn vary the occurrence of engagement between these parts during the normal operation of the piano action. By virtue of this construction of the back-check l1 and arrangement of the screw 38 adjustment of the back-check relative to the hammer butt portion 21 is a simple and convenient operation readily accomplished through the open space above the back-check.

In the modification shown in Fig. 2 the upright portion All of the back-check is comprised of wire and supported at its lower end on the whip l2, its upper end 42 being threaded and bent inwardly of the piano action in a direction toward the hammer butt portion 21. The shoe portion 43 is formed on one side with a cavity 34 having threads in the wall thereof adapted to receive in threaded en agement a tubular sleeve or adjusting screw 46 having corresponding threads on the outer peripheral surface thereof. The opposite side of the shoe portion 43 is covered with a F felt portion 4'! for operatively engaging the hammer butt portion 21. The inner peripheral surresponding to the threads on the threaded portion 42 of the back-check upright member 43. In the assembly of the back-check ii the adjustable element 23 is threadedly engaged with both the threaded portion 42 and the shoe portion d3 so that the shoe portion 63 is movably supported on the threaded portion 32 for adjustment toward and away from the butt portion 27. It is readily apparent, therefore, that with the shoe portion 43 retained stationary against rotation that rotation of the screw element 43 changes the position of the felt portion 4'! relative to the butt portion 21. It is contemplated that the adjustment portion 33 of the screw 33 be arranged so as to be extended outwardly from the shoe portion 43 at all times. The adjustment portion 38 may be formed with a plurality of fiat engaging sides for fitting a set wrench, or it may be suitably knurled or otherwise machined to provide for its engagement with a friction type wrench or the like. Thus, in the adjustment of the shoe portion 43 relative to the butt portion 2'! access to the adjustment portion 38 is readily accomplished through the space above the backcheck and between the hammer 45 and the ab stract 2!. It is obvious, of course, that the adjustment portion 58 may be manipulated by hand as well as by a supplementary gripping tool.

Yet a further modified form-of the invention is shown in Fig. 3 and is seen to include an upright portion 39 illustrated as being of wood and having a felt portion 5! at itsupper end for engaging the hammer butt portion 21, while its lower end is pivotally supported on a supporting member 52 mounted on the whip.- t2. Ih supporting member 52 is of bifurcated construction at its upper end to form a pair of spaced apart leg members adapted to receive therebetween the lower end of the upright member 49, the pivotal support being accomplished by a pin 53 or the like. The lower end of the upright member 49 is integrally constructed with a pair of oppositely projecting extensions 54 and 56 which extend over the whip l2. Threadably supported in and extending through the projection 56 is an adjustable screw 38 having its lower end in abutting engagement with a felt covering 51 provided on the top of the whip l2, while the adjustment portion at its upper end extends outwardly from the projection 53. A spring member 58 is arranged in compression between the whip l2 and the extension 54 to continuously urge the lower end of the screw 38 against the felt portion 51. Since the adjustment portion of the screw 38 is positioned to one side of the upright member 49 and above the extension 56 it is readily apparent that rotation thereof, and consequent movement of the engaging felt portion 5| relative to the hammer butt portion 21, is simply accomplished by virtue of' its being accessible through the open space provided above the back-check and between the abstract 2i and the hammer 16.

From a consideration of the above description and drawing, it is seen that the invention provides for an adjustable back-check for piano actions of drop-type which is simple of design, comprised of but a relatively few inexpensive parts, and adapted to be easily and positively adjusted relative to the piano hammer by access thereto through a space formed in the action above the back-check and between the hammer and abstract. Although the invention has been specifically described with reference to'three embodiments thereof, it is to be understood that it is not to be so limited since modifications and alterations therein can be made which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. In a piano action having a whip and a hammer with a butt portion, the combination of backcheck means for said hammer including a portion supported on and substantially fixed relative to said whi and an adjustable portion engageable with said butt portion, means movably supporting said adjustable portion on said fixed portion, and means for adjusting aid adjustable portion relative to said butt portion including means in operative engagement with said fixed and adjustable portions, which on adjustment of said adjusting means acts to retain said adjustable portion against moven ent in one direction relative to said fixed portion, with said one direction of movement corresponding to the direction or movement of said butt portion from operated to a rest position.

2. In a piano having a drop-type action including a whip in co-acting operative relation with a hammer and an abstract having a head portion, adjustable back-check means for said hammer supported on said whip intermediate said hammer and abstract and in a position entirely below the level of said abstract head portion, said back-check means including a portion fixed relative to said whip, and a shoe portion movably supported on said fixed portion, with said hammer having a butt portion operatively engageable with said shoe portion, and means in.

cluding an adjustable unit for moving said shoe portion relative to said butt portion, said adjustable unit being in operative engagement with said shoe and fixed portions, with said shoe portion being movable on said fixed portion during the adjustment of said unit but said adjustable unit retaining said shoe and fixed portions against relative movement on operative engagement of said butt portion with said shoe portion, said adjustable unit having an adjustment portion extending outwardly from said shoe portion and accessible for adjustment downwardly between said hammer and abstract.

3. In a piano action having a whip and a hammer with a butt portion, adjustable back check means for said hammer including a fixed member supported on said whip, an adjustable member operatively engageable with said butt portion, means pivotally supporting said adjustable member in a spaced relation on said fixed member, a screw member for pivotally moving said adjustable member to an adjusted position relative to said butt portion, said screw member being threadably supported in said adjustable member to one side of said pivotal means, with one end thereof in abutting engagement with said fixed member, and its opposite end projecting from said adjustable member and having an adjustment portion thereon, and a pring element arranged in compression between said adjustable and fixed members and on the other side of said pivotal means to retain said adjustable member in its adjusted position, with said screw member on operative engagement of said butt portion with said adjustable member retaining said adjustable member against movement relative to said fixed member.

4. In a piano having a drop type action including an abstract having a head portion, a hammer with a butt portion, and a whip in operative engagement with said abstract and hammer, ad-

justable back-check means for said hammer supported on said whip intermediate said hammer and abstract and in a position below the level of said hammer and abstract head portion, said back-check having a portion engageable with said hammer butt portion, means pivotally supporting said engaging portion for pivotal movement to an adjusted position relative to said hammer butt portion, means for adjustably moving said engaging portion including a screw member having an adjustment portion extending upwardly from said engaging portion so as to be accessible for manipulation downwardly between said hammer and abstract, and means retaining said engaging portion in an adjusted position.

5. In a piano action having a hammer with a butt portion and a whip in operative connection with said hammer, adjustable back-check means for said hammer having an upri ht portion engageable at one end with said butt portion, means pivotally supporting said upright portion at its opposite end on said whip, with pivotal movement of said upright portion moving said one end relative to said butt portion, said upright portion having a laterally extending projection thereon near said opposite end, adjustable means for pivotally moving said upright portion rotatably supported in and extending through said projection, with one portion thereof being engageable with said whip, and means for t ing said upright portion in its adjusted pc on as determined by the adjustment of said adjustable means.

6. In a piano action having an abstract and a hammer with a butt portion, and including a whip in operative association with said hammer and abstract, the combination of a back-check for said hammer including a substantially upright portion positioned near the bottom of said action between said abstract and hammer and below the level thereof, means pivotally-supporting said upright portion at one end on said whip, with its opposite end being engageable with said hammer butt portion, said upright portion near said one end having a pair of oppositely projecting lateral extensions, means for pivotally moving said upright portion to adjust the opposite end thereof relative to said hammer butt portion including a screw member threadably supported in one of said lateral projections, said screw member having one end thereof extending downwardly into abutting engagement with said whip, and its other end extending upwardly so as to be accessible for adjustment downwardly between said abstract and hammer, and a spring unit arranged in compression between the second of said lateral extensions and said whip for retaining said upright portion in its adjusted position.

'7. In a piano action including a whip and a hammer with a butt portion, the combination of a back-check for said hammer including a substantially upright member supported at one end on said whip, with its opposite end having a portion thereof bent inwardly of said action toward said hammer butt portion, a shoe portion engageable with said hammer butt portion, means movably supporting said shoe portion on said bent portion for movement to an adjusted position relative to said hammer butt portion, and means for moving said shoe portion to an adjusted position.

8. In a piano action having a hammer with a butt potion and an abstract, and including a whip in operative association with said hammer and abstract, the combination of a backcheck for said hammer including an upright portion supported at one end on said whip, said backcheck being positioned near the bottom of said action intermediate said action and abstract and below the level of said hammer and abstract, with the opposite end of said upright portion being threaded and bent inwardly of said action toward said butt portion, a shoe portion engageable with said hammer butt portion, and means supporting said shoe portion on said bent threaded portion for movement to an adjusted position relative to said butt portion including a tubular adjustable element, said adjustable element having oppositely handed threads on the inner and outer peripheral sides thereof, with the inner threads corresponding to the threads on said bent portion, and said shoe portion having a cavity therein threaded in correspondence with the outer threads on said adjustable element so as to receive said element therein, with said element having an adjustment portion thereon positioned between said shoe portion and upright portion to provide for the actuation of said element in the adjustment of said shoe portion from a position downwardly between said hammer and abstract.

9. Adjustable back-check means for a hammer in a drop type piano action having a whip and an abstract, including an adjustable member having a shoe portion operatively engageable with the butt portion of said hammer, supporting means carried on said whip intermediate said hammer and said abstract, means pivotally connecting said adjustable member with said supporting means, means including a screw adjustably supported in said adjustable member for adjusting said adjustable member relative to said butt portion and supporting means, said screw unit having the axis thereof in a substantially vertical plane and an adjustable portion positioned above said supporting means and laterally to one side of said shoe portion so as to be readily accessible for manipulation downward- 1y between said abstract and hammer, and means retaining said adjustable member in an adjusted position.

10. Adjustable back-check means for a hammer in a piano action having a whip, including an adjustable member having a shoe portion on one side thereof for operatively engaging the butt portion of said hammer, supporting means for said adjustable member carried on said whip, means pivotally connecting said supporting means with said adjustable member, means for adjusting said adjustable member relative to said butt portion and supporting means including an adjusting screw threadably supported in said adjustable member at the side thereof opposite said shoe portion, with said pivotal connecting means being at one end of said adjustable member and between said shoe portion and adjusting screw, means including said adjusting screw for retaining said adjustable member and supporting means in fixed relative positions on operative engagement of said butt portion with said shoe portion, and means retaining said adjustable member in an adjusted position.

JULIAN C. POTWIN. 

